The Hidex ULLA combines existing technology, latest innovations and modern usability

The Hidex ULLA addresses the increasing demand for a truly low-level liquid scintillation counter which has been absent since the discontinuation of the Quantulus 1220. Applications in hydrogeology when mapping global clean water resources, detection of biogenic carbon content in materials, or measuring trace concentrations of alpha and beta isotopes in soil, food, and drinking water require absolute accuracy and precision. Hidex have developed the next state-of-the-art counter to meet these requirements.

Ultra low background and triple coincidence detector

The ULLA achieves low background with a heavy passive lead shield and geometrically optimal active guard, which surrounds a modern triple-PMT detector facilitating exceptionally high counting efficiency, luminescence free counting, and absolute activity counting by TDCR, a metrology technique.

Vials are deionised prior to loading to remove static electricity. Cooling modules maintain the sample stability and in optimum temperature for the highest counting efficiency possible. The detector chamber can be flushed with nitrogen to remove Rn-222 gas, often found in underground mines, homes, and buildings near mountainous environments.

Exceptionally high counting efficiency

The ULLA utilizes three PMTs aligned at 120° from each other. Optimum detection geometry yields better detection geometry than conventional double coincidence detectors.

Example: Efficiency for 3H in 20ml vials

  Hidex triple detectors             Conventional double detectors
Unquenched >70% 65%
3H in water >35% 25%
3H in water, high quench 10% 5%

Alpha/beta separation

Alpha/beta separation is available as an option on the Hidex ULLA. Unique alpha/beta separation electronics with a 3D graphical AB-calibration tool developed by Hidex facilitates the reliable and sensitive detection of alpha radioisotopes in the presence of beta radioisotopes. Calibration and results validation can be done using convenient 2D/3D spectrum analysis tool without a laborious and isotope-specific misclassification run. Separation works even for unknown mixtures of alpha and beta isotopes.

Quench correction with TDCR

The 3 PMTs detector system enables Triple-to-Double Coincidence Ratio (TDCR), which is an absolute counting method for obtaining counting efficiency without the need of an external or internal radiation source. Unlike external standard methods, TDCR is a universal method applicable for both chemical and color quenching for aqueous and organic samples, as well as different cocktails and a range of radioisotopes. The TDCR method can be used for counting of typical beta radioisotopes and also for absolute activity determination of Cerenkov radiation, for example from 90Y/90Sr.

An external Eu-152 standard source is available as an option for conventional quench correction.

Alternatively, the QPC method can be used for quench indication, which uses natural cosmic radiation as the external radioactive source instead of a built-in gamma source.

You can learn more about TDCR by clicking the button below to watch our demonstration video.


Digital Pb Shield

All Hidex TDCR LSC’s uses a unique mathematical method called Digital Pb Shielding, which decrease background counts and background uncertainty. This is particularly advantageous with long count times used for:

  • H-3 in water
  • C-14 dating
  • C-14 biofuels
  • Alpha and beta isotopes in soil, food and drinking water

Luminescence-free counting

The Hidex ULLA can be used in triple coincidence only mode, which removes interference from chemiluminescence and reduces the effect of other low energy noise events. High energy beta isotopes such as C-14 can be counted immediately without the need to dark adapt. Triple Count Mode can significantly reduce background when permitted.

Hidex VALO user software

VALO is a modern user-friendly software designed specifically for Hidex LSCs. The development was based on customer feedback with special attention on usability, from building up the methods to loading of samples and evaluation of the results.

The new features include automatic extensive data reduction capabilities, including quench curve analysis, half-life correction, and reprocessing of data with new energy region of interest (ROI) and alpha/beta discriminator without remeasuring the samples.

The software is designed for a multiuser environment, enabling unlimited number of methods for different isotopes and easy data export to Excel or other programs. Users can add samples with new methods, and high priority samples while the instrument is counting.

Technical data

  • Sample capacity: 20/7/5mL: 80/192/192
  • Dimensions W69cm x H130cm xD95cm
  • Weight: 800kg

Hidex ULLA existing users 

Click the tabs below to learn more about customers and their applications for the Hidex ULLA.

André E. Lalonde AMS Laboratory, University of Ottawa, Canada

Measuring environmental tritium

The André E. Lalonde Accelerator Mass Spectrometry (AMS) Laboratory at the University of Ottawa is the first site in North America to use the Hidex ULLA, where it measures low levels of environmental tritium. The lab is Canada's national center for environmental radioisotope analysis and research in environmental sciences, health sciences, and nuclear energy. The facility measures trace concentrations of radioisotopes and other rare elements in the environment from both natural sources and human activities.

Tritium & Noble Gas Laboratory Manager Anthony Lapp said, “The Hidex ULLA gives us higher efficiencies, better results, lower uncertainties. All that lead shielding is needed to lower the background and produce lower uncertainties in the results. It has a lot of innovations and conveniences. The antistatic feature to deionise the sample vials is helpful to negate false counts or higher background, and the active guard around the triple PMTs helps give greater counting efficiencies. It’s been very exciting to have the Hidex ULLA installed and working."

You can find out more about what Anthony had to say about the Hidex ULLA and his research by clicking the button below.



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